HOUSTON -- The Houston Rockets will have to continue their post-season push without Yao Ming, who has suffered yet another serious health setback.

Yao will miss the rest of the season with a stress fracture in his left foot, the Rockets confirmed on Tuesday.

The 7-foot-6 Yao underwent an MRI and CT scan on Monday at Houston's Memorial Hermann Hospital, which revealed the problem.

Yao has been playing with pain in his foot since the all-star break, with the Rockets believing it was a sprain. The all-star centre was sent for tests to ensure it was not more serious - and returned with bad news.

"This is a very difficult day for the organization and our fans," Rockets general manager Daryl Morey said. "We've been playing exceptional ball, and Yao has been a huge part of that."

The Rockets have won 12 straight games and currently are seventh in the Western Conference standings with a 36-20 record. Yao scored 12 points and grabbed six rebounds in Sunday's 110-97 win over Chicago - numbers that were significantly down on his season averages of 22.0 points and 10.8 rebounds.

"It's a pretty big swing from a high to a low in how we were playing," Morey said.

Rockets team doctor Thomas Clanton said the cause of the injury could not be traced to a single event.

"He has not had one specific injury event to the left ankle that would really point to that being the start of this," Clanton said. "It seems to be what is typically the case in stress fractures, which is an accumulation of stresses on the bone which exceed the bone's ability to heal that stress.

"That leads to microscopic cracks which go on to be a complete crack in the bone."

Clanton said he has recommended Yao to have surgery to insert screws into his foot. But the Chinese superstar will seek second opinions, as it is possible to treat the injury without an operation.

However, both forms of treatment have an average recovery time of around four months.

"I don't know that I can tell you specifically when he will play basketball again," Clanton said. "He will not be back playing basketball again this season."

The injury could also impact Yao's availability to lead his country into the Olympic games in his home country this summer. But Clanton believes Team China's captain can be ready.

The Rockets, meanwhile, will have to try and find a way to make the playoffs without Yao, who has averaged 23.1 points and 10.2 rebounds over the last two seasons.

"We feel very confident about our playoff push," Morey said. "We've managed to step up and play well without Yao in the past, and the coaching staff and players really feel confident we're going to continue to play well and make the playoffs."

One man who may be able to help is free agent veteran Brent Barry, who is being courted by a number of teams, including the Rockets, and could make a decision as early as Tuesday evening.

"We've very committed to Brent Barry," Morey said of the team's pursuit. "Only he'll know how this will affect his decision. We still feel he's the best player to help our playoff push."

The Rockets have become accustomed to playing down the stretch without Yao, who has a long injury record.

Yao, 27, was healthy during his first three seasons in the league but has suffered since the 2005-06 campaign, when a toe injury saw him miss 21 games between December and January. He also suffered a broken foot in April 2006, ending his season.

A year later, Yao fractured the right tibia in his foot on December 23 and did not play again until early March, interrupting a season in which he had put up MVP-caliber numbers.

Morey at least found comfort in the fact that Houston has been here before.

"I think we were 20-12 last year while he was out," he said. "So I think we're ready for the challenge ahead."